A First Study on the Incidence and Prevalence of IBD in Malaysia-Results From the Kinta Valley IBD Epidemiology Study

Background: Inflammatory bowel disease [IBD] is known to be rare in the Asia Pacific region but epidemiological studies are scarce. Methods: Kinta Valley [Ipoh] was chosen as the sample population. Malaysia has a multiethnic population consisting of Malays, Chinese, and Indians. New cases over 2 years were prospectively captured as well as all known existing cases. Total numbers of the population as a whole and of each ethnic group were obtained. Incidence, prevalence, and mean incidence over two decades were then calculated. Results: There were 10 new cases of IBD diagnosed from April 2011 to April 2013. The crude incidence rates of IBD, ulcerative colitis [UC], and Crohn's disease[CD], respectively, were 0.68, 0.46, and 0.20 per 100 000 persons. The highest incidence was among the Indians, 1.91 compared with 0.35 and 0.63 per 100 000 persons among the Malays and the Chinese, respectively. The mean incidence of IBD has increased steadily from 0.07 to 0.69 per 100 000 person-years over the past two decades. The UC: CD ratio was 8:1 from 1990 to 2000 and 3.6:1 from 2000 to 2010. The prevalence rates of IBD, UC, and CD, respectively, were 9.24, 6.67, and 2.17 per 100 000 persons. The highest prevalence also was among the Indians: 24.91 compared with 7.00 and 6.90 per 100 000 persons among the Malay and Chinese races, respectively. Conclusions: The incidence and prevalence rates of IBD are low in Malaysia but the incidence appears to be increasing and marked racial differences exist. As in other Asian countries, the incidence of CD is increasing at a more rapid rate relative to UC.